Radiator pressure cap



N. WALKER Dec. 6, 1938.

RADIATOR PRESSURE CAP Filed Feb. 23, 1937 3 M, mm 779/50 m/h Patented pat, 1933 UNITED STATES RADIATOR PRESSURE CAP Nelson Walker, Flint, Mich, assignor to General Motors Corporation, Detroit, Mich, a corporav tion of Delaware Application February 23, 1937, swarm). 127,046 4 Claims. (01. 220-44) This invention relates to cooling systems for internal combustion engines and more particularly to an improvement in the detail structure of the system sealing closure for a vented filler spout shown in pending application for Patent Serial No. 116,259, filed December 17, 1936 in the name of Jesse E. Eshbaugh.

When the pressure relief valve is lifted from its seat it is balanced in space between the l opposing forces of its spring and the internal system pressure. Slight fluctuations in cooling system pressure cause violent valve vibration with an accompanying whistle which is objectionable. I

i An object of the present invention is to eliminate disturbing noise by incorporating in the valve assembly a check against sudden and free response to varying force on the valve.

A further object is to provide a. simple and inl expensive stamped metal ring having a series of circumferentially spaced spring fingers which may be applied without change in the previously designed assembly so as to be carried by the movable valve with the spring fingers acting as brake shoes in slidable engagement with the valve cage for the purpose of introducing frictional resistance to valve quiver. The device serves, incidentally, to center the valve and guide valve movement to and from its seat.

Other objects and advantages will become apparent during the course of the following description, having reference to the accompanying drawing in which Figure 1 is a side elevation of a portion of an engine and its cooling radiator in a motor vehicle installation; Figure 2 is a vertical sectional view of the radiator filler spout assembly; Figure 3 is a transverse section taken on line 3'-3 of Figure 2, and Figures 4 and 5 are detail perspective views of alternative valve centering devices.

In the drawing the radiator l is shown with the usual connections 2 and 3 leading to and from the cooling jacket of the engine cylinder block 4. The top tank of the radiator is provided with a tubuluar neck or filler spout 5 having an overflow or vent pipe 6 leading therefrom and extending downwardly beside the radiator assembly. k At its lower end the spout 5 has an inturned flange l for supporting a gasket 8 on which is seated a valve cage nested within the spout. The valve cage consists of a bottom plate 9 and a cupped stamping l which is swivelly connected by a rivet l l with a removable closure cap 12. The cap l2 carries a spring diaphragm seal III to seat on the outturned flange l4 at the top of the flller spout 5, and the flange l4 terminates in a. downwardly extending skirt IS, the lower edge of which forms a camming surface for engagement by a pair of diametrically opposite inturned lugs IS on the cap in accordance with the usual bayonet type locking connection.

Housed within the cage is a plate valve l1 carrying a gasket l8 on its underside to seat on an annular ridge l9 formed in the plate 9 beyond a central opening in the plate. A centrally apertured dome in the plate Ills closed by a spring pressed valve 20 which opens inwardly for the relief of subatmospheric pressure internally of the cooling system. Above the plate I! is a coil spring 2| seated at opposite ends on the topof the cage and the plate valve, respectively, and the elastic force of this spring yieldingly holds the valve assembly on the seat IQ for sealing the cooling system. The force of the spring 2| is preselected so that it is overcome by internal pressures of three or four pounds to communicate the system with the vent pipe 6 through suitable openings in the wall of the cage Ill. When the valve is lifted from its seat, the opposing forces of the spring 2| and internal system pressure are balanced and the valve floats in space or is suspended in an unstable state in which any slight fluctuations in internal pressure cause the valve to quiver and produce avibration in the column of pressure fluid rushing past the valve and escaping from the system.

According to the present invention the position of the elevated valve is stabilized by introducing a slight resistance to relative movement between the valve and cage and for this purpose there is interposed between the valve and the adjacent end of the coil spring 2| a ring or annulus 22 preferably stamped from spring brass and provided with a series of circumferentially spaced radial legs or fingers 23 which in assembly extend diagonally upward from the plate and terminate in reversely bent ears 24 for engagement at the bend with the wall of the cup ID. These extensions or fingers, therefore, constitute brake shoes carried by the valve in sliding engagement with the cage and the frictional resistance offered to relative movement steadies the action of the valve.

In Figure the ring is shown with two diametrically opposite spring fingers 23 and in its formation care is exercised to insure that the grain of the metal extends in the direction of the radially projecting fingers to avoid the likelihood of breakage in use. In the three fingered device of Figure 4 the grain of the metal should run in direetionoftheeenterlineofoneofthefingerssothat noinstancewillthegrainofthe metal extend normal to the center line of the fingers in the event the fingers are properly spseedapart. Thel 'igureiembodimentisdesignedtoobtain greater frictional resistance than eanbe readily hadwith a two-pronged device and to this end also heavier gage material may be used. In any event the area of friction contact is increased to insure proper functioning of the cage, a prasure relief valve contained within the cage, a valve seating spring, a member secured between the spring and the valve for movement with the valve and a series ot spring fingers carried by said'member and projected diagonally therefrom into frictional sliding engagement with the cage. v

3. In an engine cooling system, pressure relief means including a fixedly located cage element, a spring seated valve element housed within and movable relative to said cage element for the relief of pressure, a ring member carried by one of said elements and provided with a series of spring arms, said arms projecting diagonally to the other element and terminating in'reversely bent fingers to provide bearing shoes in frictional sliding engagement with the last mentioned element. r

4. In anengine cooling system, a valve cage, a spring seated valve within the cage,.a stamped metal ring carried by the valve and including a series of spring fingers extending outwardly therefrom in the direction of the grain of the metal in said ring, and bearing slidingly at their free ends on said cage.

NELSON WALKER. 

